The New Zealand golfer Danny Lee is tied for second, just one shot off the lead after a storm-affected opening day of the US Open in Pittsburgh.
Lee is at two under par after 14 holes in the second major of the year, with the little-known American Andrew Landry holding a suprise lead at three under par.
Landry ranked 624 in the world, is playing in his first major championship, and was lining up a birdie putt on this final hole when the players were forced from the course for the third and last time on the opening day.
Just nine players from the 156-strong field have completed the opening round with three separate suspensions of play because of thunder, lightening and heavy rain.
The defending champion and world number two Jordan Spieth is one-over through 11 holes, while world number three Rory McIlroy is four-over par through 13.
The other New Zealander playing, Tim Wilkinson, is yet to tee off.
The opening round had been destined to spill over into tomorrow after a weather delay in mid-morning of just over an hour and a quarter, while a line of storms passed through the area.
The treacherous Oakmont layout, known for its lightning-fast greens and sloping contours, had been softened by more than 2.5cm of rain overnight.